In conventional, the following structure is known as this kind of shredder.
There has been known a shredder comprising:
a lower casing which has an outlet in a lower portion and is formed in a rectangular plan shape;
an upper casing which is provided on the lower casing so as to be freely opened and closed by vertically oscillating movement, and is formed in a rectangular plan shape;
a rotary shaft which is rotatably provided between right and left side walls of the lower casing in the state of the axis thereof being in a lateral direction, and has a rotary blade;
a stationary blade which is provided in an inner side of a front wall of the upper casing and shreds a subject to be treated in cooperation with the rotary blade; and
a scraper which is provided in an inner side of a rear wall of the upper casing, wherein the rotary blade is positioned between the stationary blade and the scraper (refer to Japanese Unexamined Utility Model Publication No. 6-16016).
The conventional shredder has the following defects.
Since the upper casing is freely opened and closed by oscillating movement with respect to the lower casing, however, the lower casing and the upper casing are formed in the rectangular frame shape in the plan view, there has been a defect that it is hard to perform a maintenance and a cleaning.